title: Diphenyl diselenide reduces mechanical and thermal nociceptive behavioral responses after unilateral intrastriatal administration of 6-hydroxydopamine in rats.
abstract: Parkinson's disease (PD) patients, in addition to motor dysfunction, also present alterations in pain sensation. The present study characterized the antinociceptive effects of diphenyl diselenide ((PhSe)2) in a model of nociception induced by unilateral, intrastriatal 6-hydroxydopamine (6-OHDA) injection in rats. Male adult Wistar rats received 20 μg/3 μl of 6-OHDA (in saline solution containing 0.02 % of ascorbic acid) or 3 μl of vehicle into the right striatum (1.0 mm anterior, 3.0 mm lateral, and 5.0 mm ventral-with respect to the bregma). Thirty days after injection, rats received (PhSe)2 intragastrically at a dose of 10 mg/kg 1 h before behavioral tests (von Frey hairs, hot plate, tail immersion, formalin, and open field). Our results demonstrated that 6-OHDA injection to rats augmented the response frequency of von Frey hairs (VHF) stimulation, besides reducing the thermal withdrawal latency in the hot plate test. Importantly, the (PhSe)2 treatment decreased the mechanical allodynia measured by the response frequency of VHF stimulation and diminished the thermal nociception in the hot plate test in 6-OHDA-injected rats. In conclusion, these results revealed that a single oral administration of (PhSe)2 1 h prior to the accomplishment of the behavioral tests was effective to attenuate the increased mechanical and thermal nociception caused by a single intrastriatal 6-OHDA injection to rats. Furthermore, other clarifying studies are warranted to improve the evidence bases for future clinical use of (PhSe)2 as a new alternative therapy for the treatment of painful symptoms associated to PD.
authors.affiliation: Laboratório de Síntese, Reatividade e Avaliação Farmacológica e Toxicológica de Organocalcogênios, Centro de Ciências Naturais e Exatas, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil.
authors.forename: Juliana Trevisan
authors.initials: JT
authors.lastname: da Rocha
authors.forename: Simone
authors.initials: S
authors.lastname: Pinton
authors.forename: Bibiana Mozzaquatro
authors.initials: BM
authors.lastname: Gai
authors.forename: Cristina Wayne
authors.initials: CW
authors.lastname: Nogueira
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001555:Benzene Derivatives / Q000008:administration & dosage / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects; D005557:Formaldehyde / Q000008:administration & dosage / Q000633:toxicity; D006358:Hot Temperature / Q000009:adverse effects; D006930:Hyperalgesia / Q000209:etiology / Q000517:prevention & control*; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D016566:Organoselenium Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D016627:Oxidopamine / Q000008:administration & dosage / Q000633:toxicity; D010146:Pain / Q000209:etiology / Q000517:prevention & control*; D010147:Pain Measurement / Q000379:methods; D010812:Physical Stimulation / Q000379:methods; D051381:Rats; D017208:Rats, Wistar; D016896:Treatment Outcome
chemical_list: D001555:Benzene Derivatives; D016566:Organoselenium Compounds; C061132:diphenyldiselenide; D005557:Formaldehyde; D016627:Oxidopamine